This invention relates to a process for the production of novel halosilicon acids by chemically reacting a silicon tetrahalide with a dry, fine granular hydrated silica.
The hydrated silica used in this process may be produced by the chemical reaction of a dry alkali metal metasilicate with a mineral acid or an acid hydrogen containing salt. The hydrated silica compound used in the Examples was analyzed by infrared analysis, using the IR K Br disc method. The infrared analysis was very similar to the standard infrared analysis that was obtained with Mallinckrodt's hydrated silica, except for the area which shows the presence of Si--H bonds. The Si--H bonds present in the hydrated silica will reduce silver nitrate in an aqueous solution which is further evidence that Si--H bonds are present.
The molecular weight was determined from the boiling point elevation of said hydrated silica in a 6N sodium hydroxide solution and indicated a molecular weight of 78 .+-. 25 gm/mol. This type of reactive solution normally changes the molecular species. However, this would seem to indicate the absence of a polymeric form of silicate. This analysis may indicate a possible formula of HSi (OH).sub.3 which is orthosilicoformic acid and the presence of metasilicic acid (H.sub.2 SiO.sub.3) while in solution. The orthosilicoformic acid, when dried, will lose water to form silicoformic acid (H.SiO.OH).
A dry, fine granular hydrate silica (SiO.sub.2.x H.sub.2 O) produced by any of the commonly known methods may be used in this instant invention.
The silicon halide which may be employed are those which have the structural formula: EQU R.sub.y SiX.sub.z
wherein X is any halogen or mixture thereof, with the preferred being chlorine; wherein R is independently selected from the group consisting of a monovalent hydrocarbon radical, a monovalent alkoxy radical, and a monovalent aryloxy radical; wherein y is an integer from 0-3, inclusive; wherein z is an integer from 1-4, inclusive and the sum of y plus z is equal to 4. Each of the R radicals should preferrably, although not essentially, contain less than seven carbon atoms since the compounds containing these radicals are more readily available and have been found to be the most useful. The R radicals may be the same or different. Illustrative hydrocarbon, alkoxy, and aryloxy are as follows: alkyl radicals, such as methyl, ethyl, propyl, isopropyl, butyl, hexyl, octyl, decyl, dodecyl, ect.; alkenyl radicals, such as ethenyl, propenyl, etc.; alkynyl radicals such as ethynyl, propynyl, etc.; cycloalkyl radicals, such as cyclopropyl, cyclobutyl, cycloamyl, cyclohexyl, etc.; cycloalkenyl radicals, such as cyclobutenyl, cyclopentenyl, cyclohexenyl, etc.; aryl radicals, such as phenyl, anthracyl, naphthyl, etc.; aralkyl radicals, such as benzyl, phenyl-ethyl, phenyl-propyl, etc.; alkaryl radicals, such as xylyl, tolyl, ethylphenyl, p-butylphenyl, p-diisobutyl phenyl, etc. alkoxy radicals, such as methoxy, ethoxy, propoxy, etc.; and aryloxy radicals, such as phenoxy, p-butylphenoxy, etc. In addition, the hydrocarbon, alkoxy or aryloxy group may be substituted with non-interfering substituents, such as halo (i.e. chloro, bromo, fluor or iodo), nitro, sulfo, etc. The X substituent in the silicon halide is any halogen or mixture thereof, with the preferred being chlorine.
Exemplificative silicon halides include, but are not limited to, the following compounds; silicon tetrachloride; silicon tetrabromide; silicon tetrafluoride; silicon tetraiodide; methyltrichlorosilane; dimethyldichlorosilane; trimethylchlorosilane; diethyldichlorosilane; di-n-butyl-dichlorosilane; diphenyldichlorosilane; phenyltrichlorosilane; ethyl phenyldichlorosilane; methyl ethyldichlorosilane; methylpropyldichlorosilane; chloropolysilanes; chlorosilcarbanes; chlorosilaxanes; etc.
Silicon tetrachloride is the preferred silicon halide. The silicon tetrachloride may be utilized with any of the listed silicon halides or mixture of the listed silicon halides. This application will be limited to silicon tetrachloride as the silicon halide.
For the purpose of this invention the products produced by the chemical reaction of hydrated silica with a silicon tetrahalide will be called halosilicon acids.
The halosilicon acids may be used as any intermediate in the production of many organic silicon acid compounds. The halosilicon acids will react chemically with suitable organic compounds to produce organic silicon acid compounds, resinous products and/or foams. The resinous organic silicon acid products may be utilizing as protective coating on wood and metal, as calking compounds, as molding powders, as films and other uses. The organic silicon acid foams may be used for floatation, insulation, and as a structured strengthening material and other uses. The halosilicon acids may be used as catalysts to polymerize such compounds as methyl styrene, vinyl alkyl ethers, iosbutylene, butylene, ethylene, propylene, butadiene, allyl halides, alkene compounds, olefin compounds, terpenes, coumarone-indene compounds, furfuryl alcohol, furfural, ethylene oxide and other compounds. The halosilicon acid will also enter into and become a part of the polymer.